1. Field of the Invention
The present invention relates to probing apparatus for probing devices under test and more particularly, to a high frequency probe card.
2. Description of the Related Art
In a task of testing semiconductor chip, the tester needs to contact a device under test (DUT), such as a chip, through a probe card, and meanwhile the test result of the DUT can be obtained by conducting signal transmission and electric signal analysis. The aforesaid probe card is generally equipped with a plurality of fine-dimensional probes arranged in a certain pattern such that each probe may be aligned with a specific contact pad of the chip under test. When the probes contact the corresponding contact pads of the DUT respectively, they can positively transmit the test signals from the tester. In the meantime, the purpose of measuring the electric characteristics of the DUT can be achieved by the cooperation of the control and analysis processes of the probe card and the tester.
As the operating condition of electronic components tends to increasingly high speed and high frequency, the electronic components generally have a high standard specification on their electric characteristics, such as component operating condition, operating frequency and signal transmitting characteristic. Under this circumstance, the design of the probe card for electric testing needs to focus on the testing condition, the testing bandwidth and the completeness of the test signal transmission. In order to transmit the high frequency test signals effectively, the probe card selected for fulfilling such purpose must have a certain impedance matching with the tester and the device under test so as to accurately reflect the test result.
FIG. 1 shows an optical inspection device of a prior art disclosed in Taiwan Patent Publication No. 200829926. The optical inspection device, denoted by reference numeral 1, comprises an optical lens 10 and a probe card 11 including a substrate 110, an interposing plate 111 and a circuit board 112. The substrate 110 is provided with an opening 113 aligned with the openings of the interposing plate 111 and the circuit board 112 respectively for passing the optical signal from the optical lens 10 therethrough. The substrate 110 is arranged with a plurality of probes 114, each of which penetrates through the substrate 110, runs through the opening of the interposing plate 111, and penetrates through the circuit board 112 and is electrically connected with the surface of the circuit board 112. In the design of the aforesaid Taiwan patent application, it is involved with an additional work of processing the circuit board 112 with through holes or openings for the penetration of the probes 114, resulting in an increase of the manufacturing cost and a hard and complicated task in manufacturing.
In light of the above, it is desired to provide a high frequency probe card, which is impedance matching with the tester and the device under test and can be manufactured simply and easily.